CPT® Code 33746

Add-On Code

1. Indications

The transcatheter intracardiac shunt (TIS) creation by stent placement is indicated for patients with congenital cardiac anomalies that necessitate the establishment of effective intracardiac flow. The specific indications include:

• Hypoplastic Left Heart Syndrome - Particularly in cases where there is an obstructed Fontan fenestration.
• Right Ventricular Outflow Tract Obstruction - In patients who have undergone repair for congenital heart disease.
• Narrowed Stenotic Baffles - Resulting from previous surgical procedures such as Mustard, Senning, or Warden operations.

2. Procedure

The procedure for transcatheter intracardiac shunt (TIS) creation by stent placement involves several critical steps to ensure successful intervention. Initially, two venous access sites, typically the femoral and subclavian veins, along with a femoral artery, are punctured to facilitate the placement of sheaths. These sheaths allow for the introduction of diagnostic catheters, which are carefully manipulated to reach the target area within the heart. Baseline diagnostic pressures and blood sampling are performed in each of the right and left heart structures to assess hemodynamics accurately. If necessary, an angiogram of the heart chambers and vessels may be conducted by changing catheters to visualize the anatomy and identify any obstructions. A wire is then placed across the stenotic fenestration into the right atrium, which is a crucial step for subsequent interventions. The sheath is exchanged for a larger therapeutic sheath, advanced over the wire into the right atrium. In cases where the fenestration is significantly narrowed, angioplasty with a small balloon may be performed first to facilitate the passage of the sheath. Once the balloon is deflated, the sheath is advanced into the correct position. If there is complete closure of the fenestration, a transseptal perforation may be required and reported separately. An appropriate stent is then prepared and mounted onto a balloon, which is threaded over the wire up to the tip of the sheath. The entire system is carefully withdrawn just enough to center the stent over the fenestration, ensuring precise positioning, which is verified through imaging guidance. The sheath is then carefully pulled back to flare open the stent within the atrium. As the sheath is retracted further, the stent is fully deployed, with the balloon inflated to adjust the stent’s central diameter. After inflation, the balloon is carefully removed to avoid dislodging the stent, followed by the withdrawal of the wire. The remaining catheter is then utilized to perform another angiogram and measure pressures in the atrium before removal. Finally, an angiogram in the Fontan conduit may be conducted with an angiogram catheter, and left and right heart catheterization may be repeated to ensure the success of the procedure. If a second intracardiac lesion requires intervention, it is reported separately with the appropriate code.

3. Post-Procedure

Post-procedure care for patients undergoing transcatheter intracardiac shunt (TIS) creation by stent placement involves monitoring for any complications that may arise following the intervention. Patients are typically observed for signs of bleeding at the access sites, as well as for any changes in hemodynamic status. Follow-up imaging may be necessary to assess the position and function of the stent, ensuring that effective blood flow is established and maintained. Additionally, patients may require ongoing evaluation and management of their congenital heart condition, including regular follow-up appointments to monitor for any potential complications or need for further interventions. The recovery process may vary depending on the individual patient's condition and the complexity of the procedure performed.